Injects the application (war) context root into all associated resources.
Logic:
Per Virtual Host :
if 0 war:
User would have had to manually enter context.
Validate that all context elements have a context set.
else if 1 war:
fill/modify context for the context elements with the context from the war
Validate that all context elements have a context set.
else other (2+ wars):
fill context for the context elements if a single war create operation in progress.
for all modified/noop/destroy wars, update their associated context elements if the war context has changed.
validate that all context elements have a context set.